Substrate surface engineering for tailoring properties of functional ceramic thin films

摘要

Using oxide substrates for functional ceramic thin film deposition beyondtheir usual application as chemical inert, lattice-matched support for thefilms represents a novel concept in ceramic thin film research. The substratesare applied as a functional element in order to controllably modify the atomarrangement and the growth mode of ceramic prototype materials such as cupratesuperconductors and colossal magnetoresistance manganites. One example is theuse of epitaxial strain to adjust the relative positions of cations and anionsin the film and thus modify their physical properties. The other makes use ofvicinal cut SrTiO3 which enables the fabrication of regular nanoscale step andterrace structures. In YBa2Cu3O7-x thin films grown on vicinal cut SrTiO3single crystals a regular array of antiphase boundaries is generated causing ananisotropic enhancement of flux-line pinning. In the case of La-Ca-Mn-O thinfilms grown on vicinal cut substrates it could be demonstrated that magneticin-plane anisotropy is achieved.